1. Field of the Invention
This invention relates to semiconductor memory devices and more particularly to vertical channel flash memory devices.
2. Description of Related Art
1. To maintain enough current through the channel, the memory cell takes more area with traditional ETOX (EPROM with Tunnel OXide) structure since the channel is parallel to the wafer surface.
2. During the programming and the erasing procedures, the tunneling electron always needs to traverse (pass through) part of the channel area resulting in charge trapping and transconductance degradation.